Lawyers representing Saudi captive Abd al Rahim al Nashirisaid they had a duty to ensure those conversations are privateand wanted to consult their bosses and bar associations aboutwhether it would be an ethical violation for them to proceedwithout knowing who might be listening.

The judge, Army Colonel James Pohl, called a three-hourrecess to allow that. But he refused a defense request to haltthe hearings entirely until courtroom technicians could becalled to explain who had the ability to monitor theirconversations.

Nashiri is accused of directing suicide bombers to ram aboat full of explosives into the hull of the USS Cole off Yemenin 2000, causing a blast that killed 17 sailors and woundeddozens more. He could be executed if convicted of charges thatinclude murder, attempted murder and conspiring with al Qaeda.

Pohl said interfering in the attorney-client relationshipwould be "a serious matter generally deserving serious remedies"but that the defense had merely raised suspicions withoutoffering any proof of a breach.

The issue arose after a bombshell revelation last week inanother case in the war crimes tribunal at the Guantanamo BayU.S. Naval Base in Cuba. Someone outside the courtroom brieflycut the closed-circuit feed that provides sound and video topublic viewing areas during a pretrial hearing for fiveprisoners accused of plotting the Sept. 11, 2001, hijacked planeattacks.

The feed operates on a 40-second delay and a court securityofficer seated beside the judge has a button allowing him tohalt it when secret information is disclosed. The judge wasfurious that an entity outside the courtroom had the ability toclose the hearing to the public and ordered the outside killswitch disabled. Prosecutors said it was dismantled during theweekend.

The delayed feed is used for all defendants who were held insecret CIA custody before being sent to Guantanamo in 2006. Thejudge did not identify the outside monitors but said last weekit was an agency that originally classified informationpertaining to the case as "top secret."

Nashiri's military lawyer, Navy Lieutenant Commander StephenReyes, questioned whether outside monitors had the ability tolisten to whispered conversations with his client in thecourtroom or during meetings elsewhere.

Defense lawyers have speculated that if monitors had theability to mute the audio, they might be listening to privileged attorney-client conversations through eavesdroppingdevices at the court or at holding cells where lawyers meet theaccused.

"If it is the CIA that is conducting the listening, this isthe same organization that detained and tortured Mr. alNashiri," he said. "We can't just say, 'Ignore the man behindthe curtain.' We have an ethical obligation here."

The CIA has acknowledged that interrogators threatened torape Nashiri's mother, subjected him to the simulated drowningtechnique known as waterboarding and threatened him with a powerdrill, then destroyed videotapes of the sessions.

Jamil Dakwar, who is monitoring the hearing for the AmericanCivil Liberties Union's human rights program, said the burden ofproof is set exceptionally high in death penalty cases and that"If this is not investigated properly then it will leave a cloudof illegitimacy on the proceedings."